The present invention relates to a control me sliding a vehicle sliding door by a powered sliding device and, more particularly, to the safety control for detecting an abnormal movement of a sliding door, and the quality control for improving the operational feeling of a door and the durability of each part of the device by controlling the sliding speed of a door.
Conventionally, various kinds of powered sliding devices for sliding a sliding door of a vehicle body by a motor power have been proposed. These powered sliding devices have a safety device for dealing with accidents such that the body of an operator or a package is caught between the vehicle body and the door. When an occurrence of the accident has been detected, the safety device stops the door or moves the door in the opposite direction to decrease the damage caused by the accident.
Almost all of the conventional safety devices are set to detect the accident by monitoring the current value (load) of an electric motor of the powered sliding device. However, there is a problem that the change of the current value of the motor occurs behind the occurrence of the accident.
U.S. Pat. No. 5,833,301 assigned to the same assignee as the present application describes a safety device which comprises a sensor for detecting the sliding speed of a sliding door and an ammeter for detecting the load of a motor to slide the door. This safety device has an advantage that it can quickly deal with the accident by measuring the actual sliding speed of the door by using the sensor. However, an error detection of the accident may occur unless the sliding speed measured by the sensor is processed to be used.
Accordingly, it is an object of the present invention to provide a control method of a powered sliding device in which it is possible to more accurately detect accidents such that the body of an operator is caught between a vehicle body and a door, by using the sliding speed of the sliding door measured by a sensor.
Furthermore, it is another object of the present invention to provide a control method of a powered sliding device in which the operational feeling of the door and the durability of each part of the device are improved by controlling the sliding speed of the door during the beginning and ending of the actuation of the powered sliding device.